ABSTRACT
Coronavirus disease 2019 (COVID-19) patients have manifested a variety of neurological complications, and there is still much to reveal regarding the neurotropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human stem cell-derived brain organoids offer a valuable in vitro approach to study the cellular effects of SARS-CoV-2 on the brain. Here we used human embryonic stem cell-derived cortical organoids to investigate whether SARS-CoV-2 could infect brain tissue in vitro and found that cortical organoids could be infected at low viral titers and within 6 h. Importantly, we show that glial cells and cells of the choroid plexus were preferentially targeted in our model, but not neurons. Interestingly, we also found expression of angiotensin-converting enzyme 2 in SARS-CoV-2 infected cells; however, viral replication and cell death involving DNA fragmentation does not occur. We believe that our model is a tractable platform to study the cellular effects of SARS-CoV-2 infection in brain tissue.
Subject(s)
COVID-19/pathology , Choroid Plexus/pathology , Human Embryonic Stem Cells/cytology , Neuroglia/virology , Organoids/innervation , Organoids/pathology , Cells, Cultured , Choroid Plexus/cytology , Choroid Plexus/virology , Humans , Neuroglia/pathology , Neurons/virology , Organoids/cytology , SARS-CoV-2/pathogenicityABSTRACT
Non-human primate models will expedite therapeutics and vaccines for coronavirus disease 2019 (COVID-19) to clinical trials. Here, we compare acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in young and old rhesus macaques, baboons and old marmosets. Macaques had clinical signs of viral infection, mild to moderate pneumonitis and extra-pulmonary pathologies, and both age groups recovered in two weeks. Baboons had prolonged viral RNA shedding and substantially more lung inflammation compared with macaques. Inflammation in bronchoalveolar lavage was increased in old versus young baboons. Using techniques including computed tomography imaging, immunophenotyping, and alveolar/peripheral cytokine response and immunohistochemical analyses, we delineated cellular immune responses to SARS-CoV-2 infection in macaque and baboon lungs, including innate and adaptive immune cells and a prominent type-I interferon response. Macaques developed T-cell memory phenotypes/responses and bystander cytokine production. Old macaques had lower titres of SARS-CoV-2-specific IgG antibody levels compared with young macaques. Acute respiratory distress in macaques and baboons recapitulates the progression of COVID-19 in humans, making them suitable as models to test vaccines and therapies.
Subject(s)
COVID-19/veterinary , Callithrix/immunology , Lung/immunology , Macaca mulatta/immunology , Monkey Diseases/virology , Papio/immunology , SARS-CoV-2/immunology , Adaptive Immunity , Animals , Antibodies, Viral/immunology , Bronchoalveolar Lavage , Bronchoalveolar Lavage Fluid , COVID-19/diagnostic imaging , COVID-19/immunology , COVID-19/pathology , Female , Humans , Immunity, Cellular/immunology , Immunoglobulin G/immunology , Inflammation/pathology , Lung/virology , Male , Monkey Diseases/immunology , Myeloid Cells/immunology , Viral Load , Virus SheddingABSTRACT
Vaccine and antiviral development against SARS-CoV-2 infection or COVID-19 disease would benefit from validated small animal models. Here, we show that transgenic mice expressing human angiotensin-converting enzyme 2 (hACE2) by the human cytokeratin 18 promoter (K18 hACE2) represent a susceptible rodent model. K18 hACE2 transgenic mice succumbed to SARS-CoV-2 infection by day 6, with virus detected in lung airway epithelium and brain. K18 ACE2 transgenic mice produced a modest TH1/2/17 cytokine storm in the lung and spleen that peaked by day 2, and an extended chemokine storm that was detected in both lungs and brain. This chemokine storm was also detected in the brain at day 6. K18 hACE2 transgenic mice are, therefore, highly susceptible to SARS-CoV-2 infection and represent a suitable animal model for the study of viral pathogenesis, and for identification and characterization of vaccines (prophylactic) and antivirals (therapeutics) for SARS-CoV-2 infection and associated severe COVID-19 disease.
Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Disease Models, Animal , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , Brain/immunology , Brain/pathology , Brain/virology , COVID-19/immunology , COVID-19/pathology , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/pathology , Disease Susceptibility , Genetic Predisposition to Disease , Keratin-18/genetics , Lung/immunology , Lung/pathology , Lung/virology , Mice , Mice, Transgenic , Mortality , Promoter Regions, Genetic/genetics , Respiratory Mucosa/immunology , Respiratory Mucosa/pathology , Respiratory Mucosa/virology , Virus Diseases/immunology , Virus Diseases/pathologyABSTRACT
An urgent global quest for effective therapies to prevent and treat coronavirus disease 2019 (COVID-19) is ongoing. We previously described REGN-COV2, a cocktail of two potent neutralizing antibodies (REGN10987 and REGN10933) that targets nonoverlapping epitopes on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. In this report, we evaluate the in vivo efficacy of this antibody cocktail in both rhesus macaques, which may model mild disease, and golden hamsters, which may model more severe disease. We demonstrate that REGN-COV-2 can greatly reduce virus load in the lower and upper airways and decrease virus-induced pathological sequelae when administered prophylactically or therapeutically in rhesus macaques. Similarly, administration in hamsters limits weight loss and decreases lung titers and evidence of pneumonia in the lungs. Our results provide evidence of the therapeutic potential of this antibody cocktail.